Technology

New quality in muscle assessment

Myoton Technology provides a unique, reliable, accurate and sensitive way for the objective and non-invasive digital palpation of superficial skeletal muscles. Moreover, it enables measurement not only of muscles, but also tendons, ligaments, even skin and other soft biological tissues. Therefore, Myoton may become a Gold Standard in soft tissue assessment as an everyday diagnostic and monitoring device in medical practice.

Method of measurement

The method of measurement consists of recording damped natural oscillation of soft biological tissue in the form of an acceleration signal and the subsequent simultaneous computation of the parameters of State of Tension, Biomechanical and Viscoelastic properties. Damped natural oscillation is induced by an exterior, low force quick-release mechanical impulse under constant pre-load.

Five parameters for science

Myoton parameters describe a tissue from five aspects via different characteristics. In order to provide new knowledge and greater scientific value, Myoton encourages researchers to analyse all five parameters for sensitivity and responsiveness.

Acceleration Time max a max a 1 a 3 t 1 t R t 1 t T

Oscillation Frequency [Hz] characterises the Tone (intrinsic tension on the cellular level) of a muscle in its passive or resting state without any voluntary contraction (EMG signal silent).

Abnormally high muscle tone and related high intramuscular pressure restrict blood supply, which causes faster muscle fatigue and slows muscle recovery. Oscillation Frequency in the contracted state describes the State of Tension of a muscle.

Dynamic Stiffness [N/m] is the biomechanical property of a muscle that characterises the resistance to a contraction or to an external force that deforms its initial shape.

In case of abnormally high stiffness, a greater effort is required from the agonist muscle to stretch a stiff antagonist which leads to an inefficient economy of movement.

The term Dynamic Stiffness is originated from the dynamic measurement method applied in Myoton technologyThe inverse of stiffness is compliance.

Logarithmic Decrement of a tissue’s natural oscillation characterises its elasticity, but more directly the dissipation of the mechanical energy within an oscillation cycle, when tissue recovers its shape after being deformed. Elasticity is the biomechanical property of a muscle that characterises the ability to recover its initial shape after a contraction or removal of an external force of deformation.

Elasticity is inversely proportional to the decrement. Therefore if the decrement of a muscle decreases, the muscle elasticity increases. In theory a decrement of 0 (zero) represents absolute elasticity (i.e. there is no dampening of a tissue’s oscillation: in this case on Figure 1 a1 = a3). The inverse of elasticity is plasticity.

Mechanical Stress Relaxation Time [ms] is the time for a muscle to recover its shape from deformation after a voluntary contraction or a removal of an external force.

On Figure 1 Relaxation time R is the time between maximum deformation t1 and zero deformation tR.

Ratio of Deformation and Relaxation time characterises Creep (Deborah number)

Creep is the gradual elongation of a tissue over time when placed under a constant tensile stress.

On Figure 1 Deformation time comes from t1 minus tT.

What can be measured?

Limitations

Myoton technology in a standard configuration cannot be used for the measurement of:

  • Muscle groups, as its intended for single muscles
  • Thin Muscles (< 3mm)
  • Muscles with small mass (< 20 g)
  • Un-palpable muscles
  • Deep muscles located under layers of other tissues
  • Muscles covered by subcutaneous fat (>20mm)
  • Tissues that are not categorised as soft biological tissue
See possible applications